Tire-valve stem



C. E. BALDWIN TIRE VALVE STEM Filed Aug. 20 1923 gnou/Moz @vih/woo l tf. o

CHARLES EDWIN' BALDWIN, OF OCONTO, WISCONSIN, ASSIGNOR OF ONE-FOURTH T0 PHILIP ABRAIVI BADOUR, OF OCO'NTO, WISCONSIN.

TIRE-'VALVE STEM.

Application le. August 20, 1923. ySerial No. 658,403.

To all whom t may concern.'

Be it known, that I, CHARLES EDWIN BALDWIN, a citizen of the United States, residingat Qconto, in the county of Oconto and State of Wisconsin, have invented certain new and useful Improvements in Tire- Valve Stems; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others lo skilled in the art to which it appertains to make and use the same..

My invention has for its object to provide an extremely simple and compact tire indation stem which embodies also a safety blowit? 0E valvefor excesspressure and an indicator operablevto show when the proper pressure has been forcedinto the tire, as well as indicating when the tire is underinflated.

With the foregoing in view, the invention au resides in the novel subject matter hereinafter described and cl.ai`med,`the description being supplemented by the accompanying drawing:

` lEigure 1 is a side'elevation of a stem emat bodying my invention.

Ilig. 2 is a longitudinal sectional view as indicated by line 2-2 oflig. 1.

F ig. 3 is an innerend elevation.

Fig. I is `a transverse sectional view on mylinea-4 of Fig. 1.

the numeral 1 deslgnates a straight elongated cylindrical stem having an enlarged inner end 2 adapted to be clamped against the inner side of a tire tube by the usual nut (not shown). 'Ihe outer end of the stem 1 is proto vided with a threaded nipple 3 and from this nipple, an inflation bore 4 leads through one si e portion of the stem and ldischarges laterall through its enlarged end 2. The usual chraedr Valve is receivable in the bore 4 and the nipple 3 is of a size to accommodate the valve cap now commonly used. Both this nipple and the bore et are positioned ocenter to permit the formation of a second longitudinal bore 5 through the stem,

5o the inner end of this bore being in communication with a recess 6 formed in the enlarged stein end 2. A. diaphragm 7 of rubber or other desired material extends across this recess and may be secured in place by any suitable means auch as the threaded ring 8 received in the counter-bored outer end 9 of the recess.

The inflation bore i is in communication with the bore 5 by means of a suitable pressure escape port 1() near the 'outer end of the stem 1 and a second pressure escape port 11 leads from said bore 5. 'Ihe port 10 is normally closed by a slidable valve 12 positi'oned in the outer end of the y'bore 5, the active part of said valve being preferably formed of rubber, said part being preferably provided with a metal stem 13 extending outwardly in the bore 5 and surrounded by a valve seating spring 14. The outer end of this spring, in the construction shown, bears against a plug 15 threaded in the bore. The outer end of the bore 5 is preferably enlarged so as to provide a shoulder 12a to prevent the valve 12 from sliding inwardlyybeyond the ports 10 and 11.

A valve opening and pressure indicating rod 16 is loosely received in the bore 5 between the valve 12 and the diaphragm 7, the innerlend of said rod being preferably provided with a disk-like head 17 lcontacting `with the diaphragm and preventing mutilation of the latter. When the pressure in the tire rises above a predetermined extent, the diaphragm 7 moves the rod 16 to open the valve 12 which allows the air to escape through the ports 10 and 11 instead of passing through the bore 4 and entering the tire.

In order that it may be readily seen when the pressure is normal within the tire or when the latter is underinflated, I prefer to provide the stem 16 with some suitable visible indicator 18 which may well be painted thereon to be visible through an opening' 19 in the stem when the proper pressure exists. If this indicator is not visible, or appears at the lower extremity of the opening1 19, warning is given that the tire is underinflated.

IlVheninflating a tire with the improved valve stem, there is no danger of overinllation, as the diaphragm 7 moves the rod 16 to open the valve 12 as soon as the predetermined pressure within the tire is reached and hence excess pressure will blow 0E, giving warning that the tire is inflated to the number of pounds pressure predetermined by the resistance of the spring 1i. Attention is further directed tothe fact that when a tire equipped with the invention9 overheats and the contained air consequently expande and increases iss pnessuie9 suoli @fessure will operate lie diaphragm 7 te move 'lille rod 16' and unseai elle valve l2, permittinglhe eX- eess pressui'e lio escape through elle ports l0 and ll. This is particularly advantageous upon motorcycles or automobiles used in iacesi Y As excellent results ere obtainable from the details disclosed, these details are prefei'aljly followed, lout Within elle scope of the invention as claimed, numerous minor .changes may be made.

l. A Jcire inflation stem having an enlarged inner end, a longitudinal inllation bore openinnr laterally through said enlarged end, an o -cente-r recess in said enlarged end, a secnsimeee ond longitudinal linie l "i said recess7 a pressuie escape per@ n s id in ilation bore into said. secomi limeq :md :i

second piessuie escape pom'. iliom wml second bore; e, slidable spiingseaied value, in said second bore im' closing said iiis named 'ports a releasin rod in said second. lioi'e for un" seating salcl Valve, and a diapln'sgiin secured in said recess for operating said nod.

2. A structure as specified in claim l.; said rod having an indicator visible olii-@indi :in

`opening` in the stem Jfoi' indcetiny` predelzeif mined pressure in elle tire.

ln lestimony whereof .l have lieieunlo aiixed my signatne. 

